Digital BW, The Print

Kevin,

You are absolutely right - but only for conditions you tested, i.e., 
(1) the scene density range can be fully caputured on your film, and 
(2) the density range captured on film is within the capability of 
the scanner to render.

The need push (N+) to make a flat scene (low density range) more 
vibrant (more density range) is probably obsolete when you scan the 
film.  However, if your scene has a density range greater than the 
film is capable of capturing (N), than the range can never be 
regained in the scanning stage.  The same is true if the density 
range already captured on film is greater than the scanner is capable 
of rendering.  The latter probably does not apply to negative film 
which does not render dynamic range as high as color transparency 
film.  But for the former, the only way out of the mess would be a 
pull (N-) exposure.

Regards.

Shilesh

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Kevin Gulstene 
<kevin@d...> wrote:
> Traditional compensating development techniques for negatives are 
not 
> required to produce a good print when the negative is going to be 
> scanned and not printed traditionally.  It is, in most 
circumstances, 
> not material to the success of the print whether you use 'normal' 
or 
> compensated development (N+ or N-).
> 
> How's that for an iconoclastic statement!
> 
> My premise was that as long as the negative was exposed correctly 
for 
> the shadows (ie the density range of the negative was up off the 
toe) 
> it would not matter whether you developed it for a 'normal time' or 
N- 
> time or N+ time.
> 
> This makes sense to me because of how I believe the scanner and 
> software work.  When you scan a negative and apply set points you 
are 
> mapping a density range on the film to a set of numbers (say 
between 0 
> and 16383 for a 14 bit scanner), and then mapping those numbers to 
a 
> grey scale.  For example if the negative's optical density range is 
> from .4 to 1.8 then if no data is clipped by set-points then the 
> density of .4 produces a 100% black in the file and the density of 
1.8 
> produces a 0% black in the file.  If that same negative had been 
> developed differently ( say N- ignoring the 1/3 stop more exposure) 
and 
> its density range was .3 to 1.5 it would produce the same file.  .3 
> gets mapped to 100% and 1.5 gets mapped to 0%.  So the scene 
brightness 
> that produced the shadow density value of .3 or .4 produces the 
100% 
> black in the both cases  and the scene brightness that produced the 
> highlight densities of 1.5 or 1.8 produces 0% black in both cases.  
The 
> absolute value of the densities produced by the development doesn't 
> make any difference except perhaps in extreme cases with very high 
> (3.3) or very low (.5) maximum densities.
> 
> I made a simple test yesterday that seems, to me, to validate that 
> premise. Here was the set-up: I exposed took two rolls of film with 
> each frame containing the same image.  I used the new plusx.  The 
first 
> roll was at my 'normal' EI 64 ( exposed 1/60s @ 5.6) developed in 
D76 
> 1:1 for 7:15.  The second roll was exposed at EI 40 (exposed 1/60s 
@ 
> f4) and developed for 5:00 D76 1:1.
> 
> As you would expect the 'normal' negative was much denser in the 
> highlights.  I scanned one frame from each film strip on a 
sprintscan 
> 120 using vuescan.  The little density meter in vuescan (for 
whatever 
> it is worth) gave a density range of ~.35 to ~1.85 for the 'normal' 
> negative  and ~.4 to ~1.5 for the N- negative.  I set vuescan to 
scan 
> B&W, 16 bit, Neutral color balance, with black and white points set 
to 
> 0%.
> 
> The two raw scans are  different as you would expect.  The N- 
histogram 
> is offset a little further from the left  and was shorter in length 
> than the 'normal'.  The set pointed scans were virtually identical-
!!  
> I made a levels adjustment to each image to bring the white point 
in to 
> clip of the specular highlights in each image and the two images 
are 
> pretty much indistinguishable.  Their histogram data is:
> 
>                     Normal            N-
> 
> Mean             178             182
> Std Dev           52               51.9
> Median           198             204
> 
> My new zone mantra is: expose for the shadows and let the 
highlights 
> fall wherever they want.
> 
> It is arguable that a more dense negative is better because the 
scanner 
> will extract more data into the raw scan file but that does not 
seem to 
> make any practical difference.  Perhaps it would if you were to 
apply 
> aggressive curves.